Question

Between 20 and 28 students signed up for the chess club. The students could not be divided exactly into groups of 2,3,4 or 5. How many students signed up for the chess club? Show your work.

Answer 1

23

Those are not the answer:
1) 20 - can be divided by 2
2) 21 - can be divided by 3
3) 22 - can be divided by 2
4) 24 - can be divided by 2 and 4.
5) 25 - can be divided by 5
6) 26 - can be divided by 2
7) 27 - can be divided by 3
8) 28 - can be divided by 2 and 4